i purchased a truck today at auction with a 3208 engine,  problem is after it sits for an hour or so i have to crack the nuts on the injector lines and prime the hand pump on the filter until fuel comes out from under the nut.  after that it starts real quick and runs fine until i shut it off for a while,then i have to bleed again.   suggestions????

Hi Team,
first thing to do is bleed any air from the Injection Pump and Governor housings by loosening the timing bolt access bolt and crank the engine or pump the bleed pump, if fitted, until air free fuel issues from under the bolt head.
Air builds up in these areas and you end up cranking for ages to get fuel up to the injection pump plunger ports so it can pump injection fuel.
Next is to check the Bleed tap on top of the fuel Inj. Pump cover plate and also check if the check valve that is in the valve body of this valve at the return line connection boss are sealing and so stopping fuel bleeding back to the fuel tank when the engine is not running.

If the engine runs a while and stops then you may have air leaks in the fuel suction line, filters and pre-screens/water traps as these items are on the suction side of the Transfer pump on Sleeve Metering fuel systems--yes the transfer pump draws fuel thru the fuel filter pre-screens/water traps.
Clogged filters and/or pre-screens/water traps can cause air ingress to an otherwise sealed system that with fresh filters and screens/water trap would operate air free.

Lets know how you go and we can think back in time for more places to look for air issues.

It is amazing how approximately14 psi of low pressure inside the pump can get 14 psi atmospheric pressure to force air into places on suction lines, filters etc.
Check fuel return line is not clogged/crimped or been disconnected and blocked off as these pumps need some 9 gallons per hour of return fuel to keep them bled of air, cooled and lubricated hence the return orifice in the Inj. pump bleed valve that may need replacement.

Cheers,
Eddie B.

thanks eddie. i will take a look at the check valve in the fuel return. it is definitely loosing prime by bleeding back to the tank. can the hand prime pump on the fuel filter housing cause these issues also?

Hi,
the hand pump, depending on the style, should have the plunger pushed down then screwed in further to firmly lock it into place to seal off the plunger packing from leaking suction low pressure air from outside after priming the system.
On these units the priming pump plunger will usually be drawn down by the suction but needs to be screwed in further to seal it.
Cheers,
Eddie B.

yes it has the typical unscrew from the seat fuel primer pump on the filter assembly. the strange thing to me isn't so much it looses prime but that even after pumping it up even with the fuel bleed open to purge air that the engine won't start. but crack a few injector lines and hand pump until fuel flows from uder the nut the engine fires right off.

Check the throttle shaft seal on the injection pump.

thanks i will take a look at the throttle shaft. question=== wouldn't the throttle shaft seal leak fuel to the outside if it was bad?

Not always

Hi,
if the governor shaft seal is leaking air IN due to a vacuum being formed by fuel bleed back when engine is stopped, as said above, it may not leak fuel out as the seal lip is set to seal against injection pump case pressure.

We used to have to re-bush most Gov. housings on these pumps when overhauling them due to wear from the Gov. shaft operating all the time on a on highway vehicle and this can lead to the seal not sealing well as the shaft becomes off centre.

Suggest you bleed the Gov. housing at the bolt described and pictured above to rid the pump of air after it has leaked fuel back and air in each time you need to start it until you find the issue or you will have a worn out starter in short time.
Cheers,
Eddie B.

i looked it over better today. my first suspicion is the primer pump is letting air in the system.